Variability of must acidity in self pollinated Chardonnay progeny

From a total of 2,200 seedlings, obtained by self-pollination of cv. Chardonnay clone SMA 130, 250 plants were chosen and grown in a hot microclimate area. During 1986-88, morphological traits of shoot tip, leaf and bunch, as well as juice quality (sugars, pH, titratable acidity, malic and tartaric acid) were evaluated. A wide variability of the acid characteristics was noticed in the offspring. There was a significant positive correlation between total acidity and bunch size. Tartaric acid concentration was highest in medium-size bunches. A highly significant negative correlation was found between tartaric acid concentration and berry volume. More acid juice was also obtained from grapevines with a narrower apex

Wild grapevine (Vitis vinifera var. silvestris) in Italy: Distribution, characteristics and germplasm preservation-1989 report

Research on the distribution and characteristics of wild grapevines (Vitis vinifera var. silvestris) in Italy was started whose main goals are: the preservation of the germplasm by setting up plant collections;the furthering of biological knowledge about this plant;the study of relations between wild and cultivated grapevines by means of chemotaxonomic techniques;the assessment of the possibility of using wild plants for genetic improvement of grapevines.The gathering of data began in 1984. 221 sites in 15 out of the 20 Italian regions have been indicated as possible locations in which wild grapevines grow. So far, 49 of these sites have been inspected. The greatest number of individuals were found in central Italy. This population is dioecious (male/female = 1.8) with few (2.0 %) hermaphrodite examples.The leaves of the Italian wild grapevines generally have 3 lobes (57 %), but 5 to 7-lobe (36%) and non-lobed (8.9 %) plants exist. Lower variability exists with regard to leaf shape. The study of seed morphology has classified the plants into three groupe, one of which is very numerous.Two germplasm collections have been established with approximately 400 vines

Chloroplast SSR markers to assess DNA diversity in wild and cultivated grapevines

Research Not

Differential effects of canopy manipulation and shading of Vitis vinifera L. cv. Cabernet Sauvignon. Leaf gas exchange, photosynthetic electron transport rate and sugar accumulation in berries

Partial cluster and leaf removals were performed on Vitis vinifera L. cv. Cabernet Sauvignon at veraison during two years to give 4 treatments: control (C), cluster thinning (CT), leaf removal (LR) and cluster thinning + leaf removal (CT+LR). A half of each plot was shaded by a 50 % shading net at veraison (40 % berries coloured). Shading significantly reduced stomatal conductance but not CO2 assimilation rate (Pn) and carboxylation efficiency. Pn was decreased by cluster thinning and enhanced by leaf removal. Leaves of CT vines showed a photosynthetic decay 2 days after the treatment while LR leaves presented an afternoon photosynthetic enhancement 3 days after the treatment probably due to a higher photoassimilate requirement of the bunches (sink). Stomatal conductance did not totally contribute to the P-n depression or enhancement. Electron transport rate and maximum Rubisco activity were strongly affected by CT and LR suggesting that photochemical and biochemical processes were affected to a greater extent than physical processes. Juice sugar concentration was reduced by shading, an effect explained straightforwardly by the lessening of stomatal conductance. CT and LR had large effects on biochemical and photochemical processes but these were in the opposite direction to the expected effects on juice sugar concentration. It is suggested that CT increased sugar concentration because of the low fruit sink load per vine, and that LR decreased sugar concentration because of the low leaf area per vine. If cluster thinning is to be used by growers to gain increased sugar concentration it is recommended to do it at veraison; the sugar accumulation rate is then high and the adaptation of photosynthetic processes to thinning takes several days

Genetic relationships among grapevine cultivars grown in Oltrepò Pavese (Italy)

In order to evaluate the genetic distance among 47 grapevine accessions, including major and minor local cultivars grown in Oltrepò pavese (Pavia, Italy), DNA has been analysed with the AFLP approach (VOS et al. 1995). The electrophoretic analysis of the products amplified by 3 primer combinations showed high polymorphism.Furthermore, considering that DNA markers for haploid, uniparentally inherited genomes, such as the chloroplast DNA, are important indicators of pedigree, CpSSR analysis was also performed and this identified cases of maternal common origin among the analysed cultivars. The results show that these molecular tools allow univocal genotype identification and that the analysed germplasm has a wide genetic dissimilarity. Results are coherent with the postulation of a polycentric origin for the Oltrepò pavese cultivars and of a multiple varietal flow from different viticultural regions. The molecular information gathered in this research is essential for the establishment of an appropriate presentation programme of autochthonous varieties

Biodiversity of grapevines (Vitis vinifera L.) grown in the Aosta Valley

The PCR-based DNA microsatellite analysis has been applied to define genetic relationships among 19 most representative grapevine cultivars in the Aosta valley. Eighteen varieties grown nearby, in the Savoy (France), Valais (Switzerland) and Piedmont (Italy) regions, were also analysed, to verify the correlations with the Aosta cultivars inferred by the analysis of synonyms and/or morphology. Results were obtained by analysing 12 DNA microsatellite loci. High biodiversity has been recorded amongst the analysed grapevines. In some cases cultivars known with different names in the Valley and in the nearby regions displayed the same SSR allele size, proving the occurrence of synonyms. In other case, identical denominations did not correspond with the genomic identity.

Genetic studies on Trebbiano and morphologically related varieties by SSR and AFLP markers

Several grapevine varieties are named Trebbiano and have similar phenotypical characteristics (e.g. whitish berries, late ripening, vigorous growth). Other vines share many of the morphological characteristics of Trebbiano but have different names. In order to clarify the relationships between some of these varieties, a study was carried out with 7 Trebbiano varieties and 17 cultivars that are morphologically similar to Trebbiano. AFLP and SSR analyses were performed to define genetic similarity among the Trebbiano cultivars as well as between the Trebbiano cultivars and related varieties. Results show a large degree of variability between most of the cultivars and suggest that they do not share a common ancestor. Genetic analysis revealed that cv. Verdicchio is identical with Trebbiano di Soave which is very similar to Trebbiano di Lugana.

Phylogenetic analysis of grapevine cv. Ansonica growing on the island of Giglio, Italy, by AFLP and SSR markers

The geographic origin of the grapevine cultivar Ansonica (Vitis vinifera L.) grown on the island of Giglio, Tuscany, Italy, was investigated with molecular tools, i.e. AFLP and SSR (microsatellite) analysis. The scored polymorphic DNA bands were statistically analysed and the results were expressed in dendrograms showing the degree of genomic similarity among the tested cultivars: three Ansonica vines sampled in some of the oldest vineyards of the island, one Ansonica specimen grown in Tuscany, one Inzolia specimen grown in Sicily, 23 cultivars grown in different Mediterranean regions and 40 Greek cultivars. The results obtained from AFLP or SSR approaches led to equivalent conclusions: the three grapevines sampled in Giglio were indistinguishable and showed genetic similarity with cv. Ansonica grown in the Tuscan mainland and with cv. Inzolia from Sicily, Airen from Spain, Clairette from France and Roditis from Greece. The SSR analysis showed that Sideritis and Roditis have the highest genomic similarity with Ansonica among the 40 tested Greek cultivars. The molecular analysis gives conclusive evidence for the Greek origin of Ansonica grown on the island, as previously proposed on the basis of morphological and historical studies

Untersuchungen zur sortenspezifischen Mineralstoffaufnahme bei Reben

Investigations on the variety-specific uptake of minerals by grapevinesThere is a high genetic variability of the K, Ca and Mg uptake within the genus Vitis. Thus, it is possible to establish a program for the breeding of rootstocks which allow a better adaptation to the nutrient conditions of the soils and a more balanced uptake and use of the three cations. The present work is based on the so called efficiency ratio for K, Ca and Mg. This ratio expresses the amount of dry substances produced per weight unit of a nutrient element under the conditions of a limited nutrient availability. Several grapevine crossings bred in the Institute of Arboriculture, University of Milan, show a good efficiency ratio for K without Ca or Mg uptake being negatively influenced

Phylogenetic analysis of grapevine cv. Ansonica growing on the island of Giglio, Italy, by AFLP and SSR markers

The geographic origin of the grapevine cultivar Ansonica (Vitis vinifera L.) grown on the island of Giglio, Tuscany, Italy, was investigated with molecular tools, i.e. AFLP and SSR (microsatellite) analysis. The scored polymorphic DNA bands were statistically analysed and the results were expressed in dendrograms showing the degree of genomic similarity among the tested cultivars: three Ansonica vines sampled in some of the oldest vineyards of the island one Ansonica specimen grown in Tuscany, one Inzolia specimen grown in Sicily, 23 cultivars grown in different Mediterranean regions and 40 Greek cultivars. The results obtained from AFLP or SSR approaches led to equivalent conclusions: the three grapevines sampled in Giglio were indistinguishable and showed genetic similarity with cv. Ansonica grown in the Tuscan mainland and with cv. Inzolia from Sicily, Airen from Spain, Clairette from France and Roditis from Greece. The SSR analysis showed that Sideritis and Roditis have the highest genomic similarity with Ansonica among the 40 tested Greek cultivars. The molecular analysis gives conclusive evidence for the Greek origin of Ansonica grown on the island, as previously proposed on the basis of morphological and historical studies